It is up to Labor to prove the government is incapable of functioning after the Wentworth by-election, says cabinet minister Mathias Cormann.
A senior Morrison government minister has challenged Labor to put up or shut up over the soon-to-be hung parliament.
Independent MP Kerryn Phelps has maintained her lead as counting continues in the Sydney seat of Wentworth, vacated by Malcolm Turnbull after the Liberal leadership coup.
The latest Australian Electoral Commission figures published at 3.30pm on Monday show Dr Phelps on 51.06 per cent of the two-candidate preferred vote with a lead of 1559 votes.
Still to be counted were 1562 declaration votes, including postal and provisional ballots.
If as expected Dr Phelps wins the seat she will push the coalition into minority government, being one of six crossbenchers to the coalition's 75 and Labor's 69 members. One of the Liberal MPs is Speaker Tony Smith.
Government Senate leader Mathias Cormann told an estimates hearing the "pure maths" of the lower house would not change.
"Up until this weekend we needed 75 out of 148 votes (minus the retired Mr Turnbull and Mr Smith) in the House of Representatives and if the result is as it looks like it will be, we will need 75 out of 149," he said.
Asked by Labor senator Penny Wong how any laws could be passed, he said: "I don't believe the Labor Party has any capacity to stop us from being the government and if you do believe you can there are steps available to you."
"The government will continue to put forward our agenda to the parliament and we will continue to seek support for it."
He said he believed the government had confidence and supply in the lower house, based on public comments made by crossbenchers.
Getting children off Nauru first priority
Dr Phelps said she had yet to have a conversation with Prime Minister Scott Morrison but had received a text message from him saying "counting was still going on".
"Certainly I would be wanting to have a conversation with the prime minister," she told Sky News.
"The first order of business is to get kids off Nauru."
She said asylum-seeker children needed urgent medical attention in Australia.
Then an independent body should be set up to assess their resettlement options.
Asked whether Home Affairs Minister Peter Dutton should be referred to the High Court over his interests in a childcare business, she said: "We need to be very rigorous and inquiring about any legislation or motions or referrals and make sure the right decisions are made."
Three crossbenchers, Cathy McGowan, Rebekha Sharkie and Bob Katter, want the government to run its full term.
Independent Andrew Wilkie will not guarantee confidence, while Greens MP Mr Bandt said an election had to be called because "the sooner we turf out this rotten government, the better".